#ifndef demo11_h
#define demo11_h
#include <iostream>
using namespace std;
class demo11
{
public:
    // 重载运算符
    friend ostream &operator<<(ostream &, const demo11 &);
    friend istream &operator>>(istream &, demo11 &);
    friend demo11 operator+(const demo11 &, const demo11 &);
    friend demo11 operator-(const demo11 &, const demo11 &);
    friend bool operator==(const demo11 &, const demo11 &);
    demo11 &operator+=(const demo11 &);
    // 属性控制
    double get_number() const;
    string get_label() const;

private:
    double number = 12;
    double price = 10;
    string label = "test";
};

#endif // !